please make sure that if you code sign your plug-ins that the code signature is valid. We now see plug-ins that are signed, but with an invalid code signature which will trigger a crash on load in any hardened runtime enabled host.
To verify that your code signature is valid please run
codesign -v PLUGINPATH
The result should be either no output at all or
code object is not signed at all
Because unsigned code will still be loaded if allowed by the host, but invalid signed code will be rejected.